Category: Manufacturing Engineering Objective Questions

Manufacturing Engineering Multiple Choice Questions on “Introduction To Plastics”.

1. The polymerization of two or more chemically similar monomers forming a long molecular chain is termed as ____________
a) addition polymerization
b) copolymerization
c) condensation polymerization
d) step-growth polymerization
Answer: a
Clarification: Addition polymerization (also called as chain-growth polymerization) involves addition of two or more ‘similar’ monomers to form a long chain molecule. In, addition polymerization, empirical formula is the same as that of monomer. Polyolefins are formed through addition polymerization.

2. The polymerization of two or more chemically different monomers forming a long molecular chain is termed as ____________
a) addition polymerization
b) copolymerization
c) condensation polymerization
d) chain growth polymerization
Answer: b
Clarification: Copolymerization involves polymerization of two or more different monomers to form a long chain molecule. A well-known ‘Nylon 66’ is a copolymer of hexamethylenediamine and adipic acid.

3. The polymerization of two or more chemically different monomers forming a cross link polymer along with a by-product (can be either water or ammonia) is termed as ____________
a) addition polymerization
b) copolymerization
c) condensation polymerization
d) chain-growth polymerization
Answer: c
Clarification: Condensation polymerization (also called as step-growth polymerization) involves condensation (losing small molecules as by-products, usually such as water, methanol and ammonia) of different monomers to form a cross linked polymer. In, condensation polymerization, empirical formula is different as that of monomer. Polymers like polyamides, polyacetals and proteins are formed through condensation polymerization.

4. Which of the following additive is used as an initiator in polymerization reaction?
a) Benzoyl peroxide
b) Mica
c) Glass powder
d) Hydrogen peroxide
Answer: d
Clarification: Addition polymerization involves three steps for form an addition polymer, known as initiation, propagation and termination. In the initiation step, an initiator like hydrogen peroxide, easily split to form two species with a free electron attached to each.

5. Thermosetting plastics have ____________
a) 1-Degree bond
b) 2-Degree bond
c) 3-Degree bond
d) 0-Degree bond
Answer: a
Clarification: A thermosetting plastic is a polymer which gets irreversibly hardened when heated. They have a three-dimensional network of ‘1-degree’ primary bond. A well-known example of this kind are bakelite, polyester and epoxy resin, etc.

6. Which of the following is a primary bond network of thermosetting plastics?
a) 1-Dimensional
b) 3-Dimensional
c) 2-Dimensional
d) 0-Dimensional
Answer: b
Clarification: Thermosetting plastics have a three-dimensional network of ‘1-degree’ primary bond.

7. Thermoplastics have _____________
a) 1-Degree bond
b) 2-Degree bond
c) 3-Degree bond
d) 0-Degree bond
Answer: b
Clarification: A thermoplastic is a polymer which gets softened when heated. They have a one-dimensional network of ‘2-degree’ secondary bond. A well-known example of this kind are PET (polyethylene terephthalate), PVC (polyvinyl chloride), and PP (polypropylene) etc.

8. Which of the following is a secondary bond network of thermoplastics?
a) 1-Dimensional
b) 3-Dimensional
c) 2-Dimensional
d) 0-Dimensional
Answer: a
Clarification: Thermoplastics have a one-dimensional network of ‘2-degree’ secondary bond.

9. Thermoplastics become softer upon heating.
a) True
b) False
Answer: a
Clarification: Thermoplastics have 1-dimensional secondary bond structure, due to this, when heated, their individual polymer chains can slide one over other, thus making them softer.

10. Thermosetting plastics become softer upon heating.
a) True
b) False
Answer: b
Clarification: Thermosetting plastics have 2-dimensioanl primary bond structure (strong covalent cross links), thus making them stronger upon heating.

Manufacturing Engineering Multiple Choice Questions on “Cutting Fluids and Turning Process”.

1. In machining cast iron, no cutting fluid is required.
a) True
b) False
Answer: a
Clarification: None

2. The cutting fluid mostly used for machining alloy steels is :
a) water
b) soluble oil
c) dry
d) sulphurised mineral oil
Answer: d
Clarification: None

3. Cutting fluids are used to:
a) cool the tool
b) improve surface finish
c) cool the workpiece
d) all of the mentioned
Answer: d
Clarification: Functions of cutting fluids are
a) to cool the cutting tool and the workpiece
b) to lubricate the chip, tool and workpiece
c) to help carry away the chips
d) to lubricate some of the moving parts of the machine tool
e) to improve the surface finish
f) to prevent the formation of built up ridge
g) to protect the work against rusting

4. The cutting fluid mostly used for machining steel is:
a) water
b) soluble oil
c) dry
d) heavy oils
Answer: b
Clarification: Soluble oils are used for machining metals of high machinability.

5. Functions of cutting fluids are
a) to cool the cutting tool and the workpiece
b) to lubricate the chip, tool and workpiece
c) to help carry away the chips
d) all of the mentioned
Answer: d
Clarification: Functions of cutting fluids are
a) to cool the cutting tool and the workpiece
b) to lubricate the chip, tool and workpiece
c) to help carry away the chips
d) to lubricate some of the moving parts of the machine tool
e) to improve the surface finish
f) to prevent the formation of built up ridge
g) to protect the work against rusting

6. ______________ form mixtures ranging from emulsions to solutions.
a) Water miscible fluids
b) Neat oils
c) Synthetics
d) None of the mentioned
Answer: a
Clarification: Water miscible fluids form mixtures ranging from emulsions to solutions, which due to their high specific heat, high thermal conductivity, and high heat of vaporisation, are used on about 90% of all metal cutting and grinding operations.

7. Advantages of chemical fluids are
a) a very light residual film that is easy to remove
b) heat dissipation is rapid
c) good detergent properties
d) all of the mentioned
Answer: d
Clarification: Advantages of chemical fluids are
a) a very light residual film that is easy to remove
b) heat dissipation is rapid
c) good detergent properties
d) an easy concentration to control with no interference from tramp oils

8. The methods of application of cutting fluids are
a) flooding
b) jet application
c) mist application
d) all of the mentioned
Answer: d
Clarification: None.

9. In _____________ a high volume flow of the cutting fluid is generally applied on the back of the chip.
a) flooding
b) jet application
c) mist application
d) all of the mentioned
Answer: a
Clarification: In flooding, a high volume flow of the cutting fluid is generally applied on the back of the chip while in a jet application the cutting fluid, which may be either a liquid or a gas is applied in the form of a fine jet under pressure.

10. In _________ the cutting fluid, which may be either a liquid or a gas is applied in the form of a fine jet under pressure.
a) flooding
b) jet application
c) mist application
d) all of the mentioned
Answer: b
Clarification: In flooding, a high volume flow of the cutting fluid is generally applied on the back of the chip while in jet application the cutting fluid, which may be either a liquid or a gas is applied in the form of a fine jet under pressure.

11. ______________ controls both direction of chip flow and the strength of the tool tip.
a) Side rake angle
b) Relief angle
c) Rake angle
d) None of the mentioned
Answer: c
Clarification: Rake angle is important in controlling both the direction of chip flow and the strength of the tool tip.

12. _______________ acts downward on the tool tip.
a) Cutting force
b) Radial force
c) Thrust force
d) None of the mentioned
Answer: a
Clarification: The cutting force, F_C, acts downward on the tool tip and thus tends to deflect the tool downward and the workpiece upward. The cutting force supplies the energy required for the cutting operation.

13. _________ acts in the longitudinal direction.
a) Cutting force
b) Radial force
c) Thrust force
d) None of the mentioned
Answer: c
Clarification: The thrust force, F_t, acts in the longitudinal direction. It also is called the feed force, because it is in the feed direction of the tool.

14. ____________ acts in the radial direction.
a) Cutting force
b) Radial force
c) Thrust force
d) None of the mentioned
Answer: b
Clarification: The radial force, F_r, acts in the radial direction and tends to push the tool away from the workpiece.

15. For turning a small taper on a long workpiece, the suitable method is
a) by a form tool
b) by setting over the tail stock
c) by a taper turning attachment
d) none of the mentioned
Answer: b
Clarification: None

Manufacturing Engineering Multiple Choice Questions on “Ultrasonic Machining”.

1. Which of the following is an unconventional process of machining?
a) Milling
b) USM
c) Drilling
d) None of the mentioned
Answer: b
Clarification: USM stands for ultrasonic machining process and it is an unconventional process of machining.

2. Ultrasonic machining process can be used for
a) Conductors
b) Insulators
c) Metals
d) All of the mentioned
Answer: d
Clarification: Ultrasonic machining is more versatile and can be used for the metal as well as non metal.

3. Which of the following is a conventional process of machining?
a) Electro chemical machining
b) Electron beam machining
c) Ultrasonic machining
d) None of the mentioned
Answer: d
Clarification: All of the mentioned are unconventional process of machining.

4. For machining of plastic material which of the unconventional process can be used effectively?
a) Electro chemical machining
b) Electron beam machining
c) Ultrasonic machining
d) None of the mentioned
Answer: c
Clarification: Ultrasonic machining is more versatile and can be used for the metal as well as non metal.

5. Material removal rate in USM increases with
a) Decrease in volume of work material per impact
b) Increase in volume of work material per impact
c) Decrease in frequency
d) Decrease in number of particle making impact per cycle
Answer: b
Clarification: Material removal rate in USM is proportional to the volume of work material per impact.

6. Material removal rate in USM increases with
a) Decrease in volume of work material per impact
b) Decrease in volume of work material per impact
c) Decrease in frequency
d) Increase in number of particle making impact per cycle
Answer: d
Clarification: Material removal rate in USM is proportional to the number of particle making impact per cycle.

7. Material removal rate in USM increases with
a) Decrease in volume of work material per impact
b) Decrease in volume of work material per impact
c) Increases in frequency
d) Decreases in the number of particle making impact per cycle
Answer: c
Clarification: Material removal rate in Ultrasonic machining is proportional to frequency.

8. Element of machine which is used to convert high frequency electrical impulse into mechanical vibration in USM is known as
a) Tool
b) Feeding unit
c) Transducer
d) None of the mentioned
Answer: c
Clarification: Transducer is a device which is used to convert one form of energy to other.

9. Which of the following elements of USM is used to apply working force during machining operation?
a) Tool
b) Feeding unit
c) Transducer
d) None of the mentioned
Answer: b
Clarification: Feeding unit is used to apply working force during a machining operation.

10. Material removal rate in USM increases with
a) Decrease in amplitude
b) Decrease in grain size of abrasives
c) Decrease in frequency
d) Increase in amplitude
Answer: d
Clarification: Material removal rate in ultrasonic machining is proportional to amplitude.

Manufacturing Engineering Multiple Choice Questions & Answers (MCQs) on “NC Part Programming-1”.

1. Which of the following code will give point to point movement?
a) G00
b) G01
c) G56
d) G94
Answer: a
Clarification: G00 will give point to point movement.

2. Which of the following code will give linear interpolation movement?
a) G00
b) G01
c) G78
d) G65
Answer: b
Clarification: G01 will give linear interpolation movement.

3. Which of the following code will give circular interpolation in a clockwise direction?
a) G56
b) G01
c) G02
d) G47
Answer: c
Clarification: G02 will give circular interpolation in a clockwise direction.

4. Which of the following code will give circular interpolation in Counterclockwise direction?
a) G00
b) G56
c) G69
d) G03
Answer: d
Clarification: G03 will give circular interpolation in Counterclockwise direction.

5. Which the following code will produce dwell for a specified time?
a) G18
b) G65
c) G45
d) G04
Answer: d
Clarification: G04 will produce dwell for a specified time.

6. Which of the following code is used to give input of cutter offset data?
a) G30
b) G20
c) G10
d) G04
Answer: c
Clarification: G10 is used to give input of cutter offset data.

7. Which of the following code is used to select x y plane in milling?
a) G18
b) G17
c) G10
d) G04
Answer: b
Clarification: G17 is used to select x y plane in milling.

8. Which of the following code is used to select x z plane in milling?
a) G18
b) G17
c) G10
d) G04
Answer: a
Clarification: G18 is used to select x z plane in milling.

9. Which of the following code is used to select y-z plane in milling?
a) G32
b) G00
c) G02
d) G19
Answer: d
Clarification: G19 is used to select y-z plane in milling.

10. Which of the following code will change specified input values in millimeters?
a) G01
b) G00
c) G20
d) G20
Answer: c
Clarification: G20 will change specified input values in millimeters.

Manufacturing Engineering Multiple Choice Questions on “Forging Operations-1”.

1. In which of the following forging operation no special die is used?
a) Drop forging
b) Smith forging
c) Coining
d) Press forging
Answer: b
Clarification: Smith forging is also called flat die and open die forging. It includes the broad field of forging work produced between flat faced dies and possibly supplemented by stock tooling. The final shape of the forging depends on the skill of the smith for size and shape. Smith forging produces work pieces of lesser accuracy as compared to impression or closed die forging. Tooling is simple, inexpensive and allows the production on large variety of shapes.

2. In which of the following forging operation repeated hammering and closed die is used?
a) Drop forging
b) Smith forging
c) Coining
d) Press forging
Answer: a
Clarification: Hammer forging is also called as drop forging where a hammer hits the work piece repeatedly to deform it. There are different types of hammers like gravity drop, counter blow and powder hammers.

3. In which of the following forging operation instead of repeated hammering gradual force is applied?
a) Drop forging
b) Smith forging
c) Coining
d) Press forging
Answer: d
Clarification: Press forging is variation of drop-hammer forging. Unlike drop-hammer forging, press forges work slowly by applying continuous pressure or force. The amount of time the dies are in contact with the workpiece is measured in seconds (As compared to milliseconds of drop-hammer forges). The press forging operation can be done either cold or hot. The main advantage of press forging, as compared to drop-hammer forging, is its ability to deform the complete workpiece.

4. Coining and forming are two special kinds of which forging operation?
a) Upset
b) Press
c) Hubbing
d) Swaging
Answer: b
Clarification: Coining is a severe metal squeezing operation in which the flow of metal occurs at the top layers of the material and not throughout the values The operation is carried out in closed dies mainly for the purpose of producing fine details such as needed in minting coins, and metal or jewellery making. The blank is kept in the die cavity and pressure as high as five to six times the strength of material is applied. Depending upon the details required to be coined on the part, ore than one coining operation may be used.

5. Which of the following forging operation is used for parts having uniform cross section?
a) Upset
b) Press
c) Hubbing
d) Swaging
Answer: a
Clarification: In upset forging, a bar of uniform cross section usually round, is held between grooved dies, pressure is applied on the end in the direction of the axis of the bar by using a heading tool which spreads the end by metal displacement.

6. In which of the following technique shaping of a cross section of tubes or rods is done by means of repeated impacts or blows?
a) Upset
b) Press
c) Hubbing
d) Swaging
Answer: d
Clarification: Swaging is a mechanical deformation technique of reducing or shaping the cross section of rods or tubes by means of repeated impacts or blows.

7. Heading is a kind of which forging operation?
a) Piercing
b) Embossing
c) Upsetting
d) Coining
Answer: c
Clarification: A heading tool or ram is positioned perpendicular to the cross sectioned end face of a rod or bar gripped in a die. On application of pressure, the length of the rod is reduced, and the diameter is increased (upset). This manufacturing process used extensively in the production of fasteners, to form bolt heads, screw heads etc.

8. In heading to avoid buckling the length to diameter ratio should be?
a) 1:3
b) 2:3
c) 3:1
d) 2:1
Answer: c
Clarification: Buckling is characterized by a sudden sideways failure of a structural member subjected to high compressive stress, where the compressive stress at the point of failure is less than the ultimate compressive stress that the material is capable of withstanding. In upset forging, the aspect ratio (length to diameter ratio) should be 3:1.

9. Which operation is used in making raised figures on sheets with its corresponding relief on the other side?
a) Roll forging
b) Embossing
c) Coining
d) Heading
Answer: b
Clarification: Embossing is an operation in which sheet metal is drawn to shallow depths with male and female matching dies. The operation is carried out mostly for the purpose of stiffening flat panels. The operation is also sometimes used for making decoration items like number plates or name plates, jewellery, etc. Embossing operation with two dies, letters, numbers and designs on sheet-metal parts can be produced by the is operation.

10. Which of the following operation is used to make ball bearing?
a) Skew rolling
b) Roll forging
c) Press forging
d) Upsetting
Answer: a
Clarification: A special type, skew rolling is used to manufacture milling steel ball, bearing ball blanks.